TAGRA 2024

In recent years, advances in nano-scale technology have led to the use of nanoparticles in almost all areas of life. Nanoparticles have been acknowledged as one of the emerging environmental threats; however, studies in different components of environment are limited. Among the available nanoparticles, zirconium oxide nanoparticles (ZrO2-NPs) are widely used in tooth coating and cosmetic products The cytotoxicity mechanism of ZrO2-NPs has not been clarified to date. Nevertheless, generation of reactive oxygen species (ROS) by ZrO2-NPs has been considered as an important mechanism in some in vivo studies. The present study was conducted to identify the potential effects of ZrO2-NPs on diabetic rabbit tooth gum cells as well as the mechanisms of their cytotoxicity. ZrO2-NPs were characterized using scanning electron microscopy (SEM) and dynamic light scattering (DLS). Cell viability, ROS level, lipid peroxidation (MDA), mitochondrial membrane potential (MMP), glutathione count (GSH/GSSG), lysosome damage and apoptosis/ necrosis were evaluated. Biodistribution were conducted on tooth gum, liver, kidney, heart and brain tissues in the diabetic rabbit using the inductively coupled plasma optical emission spectrometry (ICP/OES). ZrO2-NPs increased ROS, MMP collapse and MDA. In contrast, GSH/GSSG and apoptosis/ necrosis were found to be changed. The ZrO2-NPs accumulated significantly more on diabetic rabbit tooth gum tissues compared with other organs. The study provided evidence that ZrO2-NPs cannot be considered completely biocompatible in the gum cell tissues of the diabetic rabbit. Before these nanoparticles can be used for human dental applications, further investigations on a wide range of cell death signaling should be performed.